Rotational dive into the water clusters on a simple sugar substrate.

Most biomolecular activity takes place in aqueous environments, and it is strongly influenced by the surrounding water molecules. The hydrogen bond networks that these water molecules form are likewise influenced by their interactions with the solutes, and thus, it is crucial to understand this reciprocal process. Glycoaldehyde (Gly), often considered the smallest sugar, represents a good template to explore the steps of solvation and determine how the organic molecule shapes the structure and hydrogen bond network of the solvating water cluster. Here, we report a broadband rotational spectroscopy study on the stepwise hydration of Gly with up to six water molecules. We reveal the preferred hydrogen bond networks formed when water molecules start to form three-dimensional (3D) topologies around an organic molecule. We observe that water self-aggregation prevails even in these early stages of microsolvation. These hydrogen bond networks manifest themselves through the insertion of the small sugar monomer in the pure water cluster in a way in which the oxygen atom framework and hydrogen bond network resemble those of the smallest three-dimensional pure water clusters. Of particular interest is the identification, in both the pentahydrate and hexahydrate, of the previously observed prismatic pure water heptamer motif. Our results show that some specific hydrogen bond networks are preferred and survive the solvation of a small organic molecule, mimicking those of pure water clusters. A many-body decomposition analysis of the interaction energy is also performed to rationalize the strength of a particular hydrogen bond, and it successfully confirms the experimental findings.

The hydrogen-bonding dynamics of water to a nitrile-functionalized electrode is modulated by voltage according to ultrafast 2D IR spectroscopy.

We report the hydrogen-bonding dynamics of water to a nitrile-functionalized and plasmonic electrode surface as a function of applied voltage. The surface-enhanced two-dimensional infrared spectra exhibit hydrogen-bonded and non-hydrogen-bonded nitrile features in similar proportions, plus cross peaks between the two. Isotopic dilution experiments show that the cross peaks arise predominantly from chemical exchange between hydrogen-bonded and non-hydrogen-bonded nitriles. The chemical exchange rate depends upon voltage, with the hydrogen bond of the water to the nitriles breaking 2 to 3 times slower (>63 vs. 25 ps) under a positive as compared to a negative potential. Spectral diffusion created by hydrogen-bond fluctuations occurs on a ~1 ps timescale and is moderately potential-dependent. Timescales from molecular dynamics simulations agree qualitatively with the experiment and show that a negative voltage causes a small net displacement of water away from the surface. These results show that the voltage applied to an electrode can alter the timescales of solvent motion at its interface, which has implications for electrochemically driven reactions.

Oxidative regulation of TDP-43 self-association by a ß-to-α conformational switch.

An evolutionarily conserved region of the TDP-43 low-complexity domain (LCD) twenty residues in length can adopt either an α-helical or ß-strand conformation. When in the latter conformation, TDP-43 self-associates via the formation of a labile, cross-ß structure. Self-association can be monitored via the formation of phase-separated protein droplets. Exposure of droplets to hydrogen peroxide leads to oxidation of conserved methionine residues distributed throughout the LCD. Oxidation disassembles the cross-ß structure, thus eliminating both self-association and phase separation. Here, we demonstrate that this process reciprocally enables formation of α-helical structure in precisely the same region formerly functioning to facilitate ß-strand-mediated self-association. We further observe that the α-helical conformation allows interaction with a lipid-like detergent and that exposure to lipids enhances the ß-to-α conformational switch. We hypothesize that regulation of this oxidative switch will prove to be important to the control of localized translation within vertebrate cells. The experimental observations reported herein were heavily reliant on studies of 1,6-hexanediol, a chemical agent that selectively dissolves labile structures formed via the self-association of protein domains of low sequence complexity. This aliphatic alcohol is shown to exert its dissociative activity primarily via hydrogen-bonding interactions with carbonyl oxygen atoms of the polypeptide backbone. Such observations underscore the central importance of backbone-mediated protein:protein interactions that facilitate the self-association and phase separation of LCDs.

Structural and functional interactions between the EF hand domain and S2-S3 loop in the type-1 ryanodine receptor ion channel.

Previous cryo-electron micrographs suggested that the skeletal muscle Ca2+ release channel, ryanodine receptor (RyR)1, is regulated by intricate interactions between the EF hand Ca2+ binding domain and the cytosolic loop (S2-S3 loop). However, the precise molecular details of these interactions and functional consequences of the interactions remain elusive. Here, we used molecular dynamics simulations to explore the specific amino acid pairs involved in hydrogen bond interactions within the EF hand-S2-S3 loop interface. Our simulations unveiled two key interactions: (1) K4101 (EF hand) with D4730 (S2-S3 loop) and (2) E4075, Q4078, and D4079 (EF hand) with R4736 (S2-S3 loop). To probe the functional significance of these interactions, we constructed mutant RyR1 complementary DNAs and expressed them in HEK293 cells for [3H]ryanodine binding assays. Our results demonstrated that mutations in the EF hand, specifically K4101E and K4101M, resulted in reduced affinities for Ca2+/Mg2+-dependent inhibitions. Interestingly, the K4101E mutation increased the affinity for Ca2+-dependent activation. Conversely, mutations in the S2-S3 loop, D4730K and D4730N, did not significantly change the affinities for Ca2+/Mg2+-dependent inhibitions. Our previous finding that skeletal disease-associated RyR1 mutations, R4736Q and R4736W, impaired Ca2+-dependent inhibition, is consistent with the current results. In silico mutagenesis analysis aligned with our functional data, indicating altered hydrogen bonding patterns upon mutations. Taken together, our findings emphasize the critical role of the EF hand-S2-S3 loop interaction in Ca2+/Mg2+-dependent inhibition of RyR1 and provide insights into potential therapeutic strategies targeting this domain interaction for the treatment of skeletal myopathies.

Improved resolution of 3-mercaptopropionate dioxygenase active site provided by ENDOR spectroscopy offers insight into catalytic mechanism.

3-mercaptopropionate (3MPA) dioxygenase (MDO) is a mononuclear nonheme iron enzyme that catalyzes the O2-dependent oxidation of thiol-bearing substrates to yield the corresponding sulfinic acid. MDO is a member of the cysteine dioxygenase family of small molecule thiol dioxygenases and thus shares a conserved sequence of active site residues (Serine-155, Histidine-157, and Tyrosine-159), collectively referred to as the SHY-motif. It has been demonstrated that these amino acids directly interact with the mononuclear Fe-site, influencing steady-state catalysis, catalytic efficiency, O2-binding, and substrate coordination. However, the underlying mechanism by which this is accomplished is poorly understood. Here, pulsed electron paramagnetic resonance spectroscopy [1H Mims electron nuclear double resonance spectroscopy] is applied to validate density functional theory computational models for the MDO Fe-site simultaneously coordinated by substrate and nitric oxide (NO), (3MPA/NO)-MDO. The enhanced resolution provided by electron nuclear double resonance spectroscopy allows for direct observation of Fe-bound substrate conformations and H-bond donation from Tyr159 to the Fe-bound NO ligand. Further inclusion of SHY-motif residues within the validated model reveals a distinct channel restricting movement of the Fe-bound NO-ligand. It has been argued that the iron-nitrosyl emulates the structure of potential Fe(III)-superoxide intermediates within the MDO catalytic cycle. While the merit of this assumption remains unconfirmed, the model reported here offers a framework to evaluate oxygen binding at the substrate-bound Fe-site and possible reaction mechanisms. It also underscores the significance of hydrogen bonding interactions within the enzymatic active site.

Using a cellulose-complementary oligosaccharide as a tool to probe exposed cellulosic surfaces in cotton fibres and growing plant cell walls.

Cellulosic microfibrils in plant cell walls are largely ensheathed and probably tethered by hydrogen-bonded hemicelluloses. Ensheathing may vary developmentally as hemicelluloses are peeled to enable cell expansion. We characterised a simple method to quantify ensheathed versus naked cellulosic surfaces based on the ability to adsorb a radiolabelled 'cellulose-complementary oligosaccharide', [3H]cellopentaitol. Filter-paper (cellulose) adsorbed 40% and >80% of aqueous 5 nM [3H]cellopentaitol within ∼1 and ∼20 h respectively. When [3H]cellopentaitol was rapidly dried onto filter-paper, ∼50% of it was desorbable by water, whereas after ∼1 day annealing in aqueous medium the adsorption became too strong to be reversible in water. 'Strongly' adsorbed [3H]cellopentaitol was, however, ∼98% desorbed by 6 M NaOH, ∼50% by 0.2 M cellobiose, and ∼30% by 8 M urea, indicating a role for hydrogen-bonding reinforced by complementarity of shape. Gradual adsorption was promoted by kosmotropes (1.4 M Na2SO4 or 30% methanol), and inhibited by chaotropes (8 M urea), supporting a role for hydrogen-bonding. [3H]Cellopentaitol adsorption was strongly competed by non-radioactive cello-oligosaccharides (Cell2-6), the IC50 (half-inhibitory concentration) being highly size-dependent: Cell2, ∼70 mM; Cell3, ∼7 mM; and Cell4-6, ∼0.05 mM. Malto-oligosaccharides (400 mM) had no effect, confirming the role of complementarity. The quantity of adsorbed [3H]cellopentaitol was proportional to mass of cellulose. Of seven cottons tested, wild-type Gossypium arboreum fibres were least capable of adsorbing [3H]cellopentaitol, indicating ensheathment of their microfibrillar surfaces, confirmed by their resistance to cellulase digestion, and potentially attributable to a high glucuronoarabinoxylan content. In conclusion, [3H]cellopentaitol adsorption is a simple, sensitive and quantitative way of titrating 'naked' cellulose surfaces.

Design of Soft/Hard Interface with High Adhesion Energy and Low Interfacial Thermal Resistance via Regulation of Interfacial Hydrogen Bonding Interaction.

Adhesion ability and interfacial thermal transfer capacity at soft/hard interfaces are of critical importance to a wide variety of applications, ranging from electronic packaging and soft electronics to batteries. However, these two properties are difficult to obtain simultaneously due to their conflicting nature at soft/hard interfaces. Herein, we report a polyurethane/silicon interface with both high adhesion energy (13535 J m-2) and low thermal interfacial resistance (0.89 × 10-6 m2 K W-1) by regulating hydrogen interactions at the interface. This is achieved by introducing a soybean-oil-based epoxy cross-linker, which can destroy the hydrogen bonds in polyurethane networks and meanwhile can promote the formation of hydrogen bonds at the polyurethane/silicon interface. This study provides a comprehensive understanding of enhancing adhesion energy and reducing interfacial thermal resistance at soft/hard interfaces, which offers a promising perspective to tailor interfacial properties in various material systems.

Efficient Proton Transfer and Charge Separation within Covalent Organic Frameworks via Hydrogen-Bonding Network to Boost H2O2 Photosynthesis.

Photocatalytic synthesis based on the oxygen reduction reaction (ORR) has shown great promise for H2O2 production. However, the low activity and selectivity of 2e- ORR result in a fairly low efficiency of H2O2 production. Herein, we propose a strategy to enhance the proton-coupled electron transfer (PCET) process in covalent organic frameworks (COFs), thereby significantly boosting H2O2 photosynthesis. We demonstrated that the construction of a hydrogen-bonding network, achieved by anchoring the H3PO4 molecular network on COF nanochannels, can greatly improve both proton conductivity and photogenerated charge separation efficiency of COFs. Thus, COF@H3PO4 exhibited superior photocatalytic performance in generating H2O2 without sacrificial agents, with a solar-to-chemical conversion efficiency as high as 0.69%. Results indicated that a much more localized spatial distribution of energy band charge density on COF@H3PO4 led to efficient charge separation, and the small energy barrier of the rate-limiting step from *OOH to H2O2 endowed COF@H3PO4 with higher 2e- ORR selectivity.

High Performance Nacre Fibers by Engineering Interfacial Entanglement.

Biological materials exhibit fascinating mechanical properties for intricate interactions at multiple interfaces to combine superb toughness with wondrous strength and stiffness. Recently, strong interlayer entanglement has emerged to replicate the powerful dissipation of natural proteins and alleviate the conflict between strength and toughness. However, designing intricate interactions in a strong entanglement network needs to be further explored. Here, we modulate interlayer entanglement by introducing multiple interactions, including hydrogen and ionic bonding, and achieve ultrahigh mechanical performance of graphene-based nacre fibers. Two essential modulating trends are directed. One is modulating dynamic hydrogen bonding to improve the strength and toughness up to 1.58 GPa and 52 MJ/m3, simultaneously. The other is tailoring ionic coordinating bonding to raise the strength and stiffness, reaching 2.3 and 253 GPa. Modulating various interactions within robust entanglement provides an effective approach to extend performance limits of bioinspired nacre and optimize multiscale interfaces in diverse composites.

Tunable Surface Wettability via Terahertz Electrowave Controlled Vicinal Subnanoscale Water Layer.

Achieving timely, reversible, and long-range remote tunability over surface wettability is highly demanded across diverse fields, including nanofluidic systems, drug delivery, and heterogeneous catalysis. Herein, using molecular dynamic simulations, we show, for the first time, a theoretical design of electrowetting to achieve remotely controllable surface wettability via using a terahertz wave. The key idea driving the design is the unique terahertz collective vibration identified in the vicinal subnanoscale water layer, which is absent in bulk water, enabling efficient energy transfer from the terahertz wave to the rotational motion of the vicinal subnanoscale water layer. Consequently, a frequency-specific alternating terahertz electric field near the critical strength can significantly affect the local hydrogen-bonding network of the contact water layer on the solid surface, thereby achieving tunable surface wettability.

Structure and intermolecular interactions in ionic liquid 1-ethyl-3-methylimidazolium bromide and its aqueous solutions investigated by vibrational spectroscopy and quantum chemical computations.

The recently developed efficient protocol to explicit quantum mechanical modeling of structure and IR spectra of liquids and solutions (S. A. Katsyuba, S. Spicher, T. P. Gerasimova, S. Grimme, J. Phys. Chem. B 2020, 124, 6664) is applied to ionic liquid (IL) 1-ethyl-3-methylimidazolium bromide (EmimBr), its C2-deuterated analog [Emim-d]Br and its aqueous solutions. It is shown that the solvation strongly modifies frequencies and IR intensities of the CH/CD stretching vibrations (νCH/νCD) of the imidazolium ring. The main vibrational spectroscopic features of the neat IL are reproduced by the simulations for a cluster (EmimBr)9, in which all three imidazolium CH moieties of the solvated cation form short contacts with three Br- anions, and another two Br- anions are located on top and bottom of imidazolium ring. Cluster models of aqueous solutions reproduce the experimental vibrational frequencies of actual solutions, provided that the Br- anion of solvated contact ion pair (CIP) is situated on top of imidazolium ring, and CH/CD moieties of the latter participate in short contacts with surrounding water molecules. Both structural and spectroscopic analysis allow to interpret the short contacts CH/CD⋯Br- and CH/CD⋯OH2 as hydrogen bonds of approximately equal strength. Enthalpies of bonding of these liquid-state H-bonds, estimated with the use of empirical correlations, amount to ca. 1.4 kcal⋅mol-1, while the analogous estimates obtained for the gas-phase charged species [Emim]2Br+ increase to 5.6 kcal⋅mol-1. It is shown that formation of solvent-shared ion pair (SIP) in aqueous solution, where the counterions of IL are separated by two water molecules H-bonded to a Br- anion, produces frequency shifts ΔνCH/CD, strongly different from the case of CIP formation. This difference can be used for IR/Raman spectroscopic differentiation of the type of solvated ion pairs of EmimBr or other related ILs.

Visible Light-Activated Ultralong-Lived Triplet Excitons of Carbon Dots for White-Light Manipulated Anti-Counterfeiting.

Room temperature phosphorescence (RTP) has emerged as an interesting but rare phenomenon with multiple potential applications in anti-counterfeiting, optoelectronic devices, and biosensing. Nevertheless, the pursuit of ultralong lifetimes of RTP under visible light excitation presents a significant challenge. Here, new phosphorescent materials that can be excited by visible light with record-long lifetimes are demonstrated, realized through embedding nitrogen doped carbon dots (N-CDs) into a poly(vinyl alcohol) (PVA) film. The RTP lifetime of the N-CDs@PVA film is remarkably extended to 2.1 s excited by 420 nm, representing the highest recorded value for visible light-excited phosphorescent materials. Theoretical and experimental studies reveal that the robust hydrogen bonding interactions can effectively reduce the non-radiative decay rate and radiative transition rate of triplet excitons, thus dramatically prolong the phosphorescence lifetime. Notably, the RTP emission of N-CDs@PVA film can also be activated by easily accessible low-power white-light-emitting diode. More significantly, the practical applications of the N-CDs@PVA film in state-of-the-art anti-counterfeiting security and optical information storage domains are further demonstrated. This research offers exciting opportunities for utilizing visible light-activated ultralong-lived RTP systems in a wide range of promising applications.

Intermolecular Assembly of Dual Hydrogen Bonding Regio-Isomers Generates High-Performance AIE Probes.

Regio-isomers are utilized to design innovative AIE luminogens (AIEgens) by regulating molecular aggregation behavior. However, relevant examples are limited, and the underlying mechanism is not fully understood. Herein, a regio-isomer strategy is used to develop AIEgens by precisely regulating the intermolecular interactions in the solid state. Among the regio-isomers it is investigated, ortho- isomer (DCM-O3-O7) exhibits enhanced AIE-activity than the para- isomer (DCM-P6), and the size of the ortho- substituents is crucial for the AIE performance. The underlying mechanism of the strategy is revealed using DFT calculations and single-crystal analysis. Dual hydrogen bonds (C─H∙∙∙π and C─H∙∙∙N) are generated between the molecules, which contributes to form dimers, tetramers, and 1D supramolecular structures in the crystal. By restricting intramolecular motion and attenuating π-π interactions, solid-state fluorescence is significantly enhanced. This strategy's effectiveness is validated using other donor-acceptor fluorophores, with DCM-O6 and its analogues serving as efficient probes for bioimaging applications. Notably, DCM-OM, which bears a morpholinyl instead of piperidinyl group, displayed strong lysosome-targeting ability and photostability; DCM-OP, incorporated by the hydrophilic quaternary ammonium group, exhibited wash-free imaging and cell membrane-targeting capabilities; and DCM-O6 nanoparticles enabled high-fidelity in vivo tumor imaging. Therefore, this strategy affords a general method for designing bright AIEgens.

Bio-Inspired Carbon Dots as Malondialdehyde Indicator for Real-Time Visualization of Lipid Peroxidation in Depression.

Brain lipidic peroxidation is closely associated with the pathophysiology of various psychiatric diseases including depression. Malondialdehyde (MDA), a reactive aldehyde produced in lipid region, serves as a crucial biomarker for lipid peroxidation. However, techniques enabling real-time detection of MDA are still lacking due to the inherent trade-off between recognition dynamics and robustness. Inspired by the structure of phospholipid bilayers, amphiphilic carbon dots named as CG-CDs targeted to cell membrane are designed for real-time monitoring of MDA fluctuations. The design principle relies on the synergy of dynamic hydrogen bonding recognition and cell membrane targetability. The latter facilitates the insertion of CG-CDs into lipid regions and provides a hydrophobic environment to stabilize the labile hydrogen bonding between CG-CDs and MDA. As a result, recognition robustness and dynamics are simultaneously achieved for CG-CDs/MDA, allowing for in situ visualization of MDA kinetics in cell membrane due to the instant response (<5 s), high sensitivity (9-fold fluorescence enhancement), intrinsic reversibility (fluorescence on/off), and superior selectivity. Subsequently, CG-CDs are explored to visualize nerve cell membrane impairment in depression models of living cells and zebrafish, unveiling the extensive heterogeneity of the lipid peroxidation process and indicating a positive correlation between MDA levels and depression.

Role of Hydrogen Bonding on the Design of New Hybrid Perovskites Unraveled by Machine Learning.

Selecting a set of reactants to accurately design a new low dimensional hybrid perovskite could greatly accelerate the discovery of materials with great potential in photovoltaics, or solid-state lighting. However, this design is challenging as most hybrid metal halides are not perovskites and no feature is clearly associated to the structural characteristics of the inorganic metal halide network. This work first demonstrates that the organic molecules are key parameters to determine the structure type of the inorganic network (i.e., perovskite versus non-perovskite). Then, machine learning (ML) algorithms are used to identify the key features of the organic cations leading to the perovskite structure type. Using a large dataset of hybrid metal halides, this work extracts the organic molecules of all hybrid lead halide compounds, calculates 2756 molecular descriptors and fingerprints for each of these molecules, and are able to predict through ML techniques if a specific organic amine will lead to the perovskite type with an accuracy up to 88.65%. Descriptors related to hydrogen bonding are identified as important features. Thus, a simple but reliable design principle could be demonstrated: the presence of primary ammonium cation is the primary condition to prepare hybrid lead halide perovskites regardless of their dimensionalities.

Block Copolymer Self-assembly: Exploitation of Hydrogen Bonding for Nanoparticle Morphology Control via Incorporation of Triazine Based Comonomers by RAFT Polymerization.

Synthesis of polymeric nanoparticles of controlled non-spherical morphology is of profound interest for a wide variety of potential applications. Self-assembly of amphiphilic diblock copolymers is an attractive bottom-up approach to prepare such nanoparticles. In the present work, RAFT polymerization is employed to synthesize a variety of poly(N,N-dimethylacrylamide)-b-poly[butyl acrylate-stat-GCB] copolymers, where GCB represents vinyl monomer containing triazine based Janus guanine-cytosine nucleobase motifs featuring multiple hydrogen bonding arrays. Hydrogen bonding between the hydrophobic blocks exert significant influence on the morphology of the resulting nanoparticles self-assembled in water. The Janus feature of the GCB moieties makes it possible to use a single polymer type in self-assembly, unlike previous work exploiting, e.g., thymine-containing polymer and adenine-containing polymer. Moreover, the strength of the hydrogen bonding interactions enables use of a low molar fraction of GCB units, thereby rendering it possible to use the present approach for copolymers based on common vinyl monomers for the development of advanced nanomaterials.

Eu3+-Directed Supramolecular Metallogels with Reversible Quadruple-Stimuli Response Behaviors.

Smart luminescent materials that have the ability to reversibly adapt to external environmental stimuli and possess a wide range of responses are continually emerging, which place higher demands on the means of regulation and response sites. Here, europium ions (Eu3+)-directed supramolecular metallogels are constructed by orthogonal self-assembly of Eu3+ based coordination interactions and hydrogen bonding. A new organic ligand (L) is synthesized, consisting of crown ethers and two flexible amide bonds-linked 1,10-phenanthroline moieties to coordinate with Eu3+. Synergistic intermolecular hydrogen bonding in L and Eu3+-L coordination bonding enable Eu3+ and L to self-assemble into shape-persistent 3D coordination metallogels in MeOH solution. The key to success is the utilization of crown ethers, playing dual roles of acting both as building blocks to build L with C2-symmetrical structure, and as the ideal monomer for increasing the energy transfer from L to Eu3+'s excited state, thus maintaining the excellent luminescence of metallogels. Interestingly, such assemblies show K+, pH, F-, and mechano-induced reversible gel-sol transitions and tunable luminescence properties. Above findings are useful in the studies of molecular switches, dynamic assemblies, and smart luminescent materials.

Constructing 2D Phthalocyanine Covalent Organic Framework with Enhanced Stability and Conductivity via Interlayer Hydrogen Bonding as Electrocatalyst for CO2 Reduction.

Fabricating COFs-based electrocatalysts with high stability and conductivity still remains a great challenge. Herein, 2D polyimide-linked phthalocyanine COF (denoted as NiPc-OH-COF) is constructed via solvothermal reaction between tetraanhydrides of 2,3,9,10,16,17,23,24-octacarboxyphthalocyaninato nickel(II) and 2,5-diamino-1,4-benzenediol (DB) with other two analogous 2D COFs (denoted as NiPc-OMe-COF and NiPc-H-COF) synthesized for reference. In comparison with NiPc-OMe-COF and NiPc-H-COF, NiPc-OH-COF exhibits enhanced stability, particularly in strong NaOH solvent and high conductivity of 1.5 × 10-3 S m-1 due to the incorporation of additional strong interlayer hydrogen bonding interaction between the O-H of DB and the hydroxy "O" atom of DB in adjacent layers. This in turn endows the NiPc-OH-COF electrode with ultrahigh CO2-to-CO faradaic efficiency (almost 100%) in a wide potential range from -0.7 to -1.1 V versus reversible hydrogen electrode (RHE), a large partial CO current density of -39.2 mA cm-2 at -1.1 V versus RHE, and high turnover number as well as turnover frequency, amounting to 45 000 and 0.76 S-1 at -0.80 V versus RHE during 12 h lasting measurement.

Highly Durable Silicone-Based Elastomers Achieved Through the Synergy of Bi-Incompatible Soft Segments and Multi-Scale Hydrogen Bonds.

Developing a silicone elastomer with high strength, exceptional toughness, good crack tolerance, healability, and recyclability, poses significant challenges due to the inherent trade-offs between these properties. Herein, the design of silicone-based elastomers with a nanoscopic microphase separation structure and comprehensive mechanical properties is achieved by combining bi-incompatible soft segments and multi-scale hydrogen bonds. The formation of multi-scale hydrogen bonds involving urethane, urea, and 2-ureido-4[1H]-pyrimidinone (UPy) facilitates efficient reversible crosslinking of the synthesized polymer containing thermodynamically incompatible poly(dimethylsiloxane) (PDMS) and poly(propylene glycol) (PPG). The dynamic dissociation and recombination of hydrogen bonds, coupled with the forced compatibility and spontaneous separation of bi-incompatible soft segments, can effectively dissipate energy, particularly in the crack region during the stretching process. The obtained silicone-based elastomer exhibits a high break strength of 8.0 MPa, good elongation at break of 1910%, ultrahigh toughness of 67.8 MJ m-3, and unprecedented fracture energy of 31.8 kJ m-2 while maintaining their thermal stability, hydrophobicity, healability, and recyclability. This resilient and long-lasting silicone-based elastomer exhibits significant potential for use in flexible electronic devices.

Multifunctional Iron Selenate Sheath of Fe-Based Anode Achieving High-Rate Capacity-Durability Combination of Aqueous Hybrid Energy Storage Devices.

The introduction of battery-type cathode has been commonly considered a preferred approach to boost the energy density of aqueous hybrid energy storage devices (AHESDs) in alkalic systems, but AHESDs with both high energy density and power density are rare due to the great challenge in designing battery-type anode materials with high rate and durability comparable to capacitive-type carbon anodes. In this paper, a well-hydrated iron selenate (FeSeO) sheath is constructed around FeOOH nanorods by a facile electrochemical activation, demonstrating the unique multifunction in fasting charge diffusion, promoting the dissociation of H2O, and inhibiting the irreversible phase transition of FeOOH to inert γ-Fe2O3, which endow the hydrated sheath coated Fe-based anodes with an impressive rate capability and superior durability. Thanks to the comprehensive performance of this Fe-based anode, the assembled AHESD delivered a high energy density of 117 Wh kg-1 with the extraordinary durability of almost 100% capacity retention after 40 000 cycles. Even at an ultrahigh power density of 27 000 W kg-1, an impressive energy density of 65 Wh kg-1 can be achieved, which rivals previously reported energy-storage devices.